Rebels walk with their weapons at a checkpoint in a street in Tripoli August 26, 2011. People of Tripoli ventured out to mosques on Friday, praying for peace and offering thanks for the fall of Muammar Gaddafi, though the Libyan capital remained locked down and dangerous as rebel fighters hunted the fugitive strongman.

TRIPOLI (Reuters) - Mass killings that have taken place in Tripoli since the fall of Libya's Muammar Gaddafi provide a harrowing warning that more carnage may lie ahead.

Millions of Libyans have supported the six-month rebellion against Gaddafi in hope of a peaceful future. Many in the new leadership have called for reconciling with their foes.

But as bodies lay in fetid piles in the streets of the capital this week, Libyans faced the prospect that, as in Iraq in 2003, the fall of a dictator could mark the beginning, rather than the end, of the war's most violent phase.

Experts say the country is now at a crossroads, and a failure by the new leadership to rein in its own side could send Libya careening down a path toward uncontrollable bloodletting.

"If there are a lot of reprisal killings, then the potential for the thing to spiral into bloody violence is immense," said British-based defence analyst Tim Ripley. "Overall, Libya's future is in the balance."

Gaddafi, who has eluded rebels now in control of Tripoli, had prophesied an apocalypse of violence if he were toppled.

He and his inner circle could prove to be ruthless and formidable insurgents in the country they ruled for 42 years.

"If the insurgency continues and the remaining pro-Gaddafi forces are not persuaded of the benefits of abandoning their struggle, then any confrontation is bound to become increasingly bitter as time passes," said George Joffe, a North Africa expert at Cambridge University.

"What the remnants of the regime will hope for is to create such deep cleavages as to make reconciliation impossible."

FETID CORPSES

The scenes I witnessed last week as Gaddafi's forces made a last stand in Tripoli's Abu Salim district were as disturbing as any I have seen in 17 years as a frontline war correspondent.

At a tented camp at a traffic circle near the frontline, I saw at least two dozen bodies of Gaddafi militia members riddled with bullets. Several had been killed while their hands were tied behind their backs with plastic cuffs.

One lay in an abandoned ambulance, still strapped to the gurney. Nearby, four corpses lay in a white field hospital tent, one with a drip still in his arm.

Since then, Reuters and other news organisations have found scores of other bodies in the capital, especially in Abu Salim, home to many Gaddafi government officials and their families.

On Friday came the discovery of the abandoned Abu Salim hospital building, full of corpses lying in cots.

The exact circumstances of the killings are still not clear, but these were not fighters left where they were killed on the battlefield. Gaddafi's supporters will doubtless blame the rebels for carrying out large-scale revenge killings.

Three African captives I saw in a rebel pickup truck were convulsed with fear. One wept and repeated over and over: "I do not know Gaddafi. I do not know Gaddafi. I am here for working."

I also heard allegations of atrocities committed by fleeing Gaddafi loyalists in the past week.

A man in a hospital told me he was one of only two survivors among prisoners in a government jail cell, ordered to the floor and sprayed with bullets by fleeing guards as rebels advanced.

He cowered for hours with the corpses before he was rescued.

Under an awning in the hospital car park lay the bloated and flyblown bodies of what doctors said were 15 victims of that incident.

Whichever side perpetrated the most violence, the new authorities can expect to be held to the higher standard, not least by Western powers whose warplanes helped install them in power under a United Nations mandate to protect civilians.

NEW LEADERS DIVIDED

Libya's new leaders have repeatedly called for national unity and reconciliation and ordered their fighters to avoid revenge killings. It seems likely that most Libyans want a future of peace, not more violence, after decades of repression.

But anti-Gaddafi forces include hardened fighters, some of whom have operated more or less independently, and who may not share the determination of the rebel National Transitional Council (NTC) to prevent violence.

"The fact that the NTC has called for reconciliation has not been accepted universally by rebel groups," said Joffe.

"The NTC is not yet a fully coherent body. There are lots of different factions inside it that have got their own agendas. Some of them do believe that they have to eradicate the old regime. That's something that the leadership have to in some way cope with, and they haven't done so yet. It's a mammoth task."

The potential for violence to spiral is vast.

Libya is a weakly-governed nation split by tribal rivalries. Most of its 6 million people live in cities perched precariously on the edge of the Sahara, fed and watered by the state from the income generated by oil exports, which have yet to resume.

Like Iraq's ousted Baathists after the downfall of Saddam Hussein, Gaddafi loyalists will know exactly which ancient feuds to stoke to stir more violence, and which infrastructure to target to make life unbearable for the public.

The rebels are mostly organised on local or tribal lines. The trucks in which they prowl Tripoli are spray-painted with names of their distant home towns -- Misrata, Zintan, Benghazi.

Some cities remain in pro-Gaddafi hands, above all his birth-place Sirte, which straddles the coastal highway linking east and west Libya. Rebels are trying to negotiate its surrender, even as they advance towards it from two directions.

Gaddafi forces may still make a final stand there -- and if the streets of Abu Salim last week are any guide, that could precipitate the Libyan conflict's bloodiest battle yet. (Editing by Richard Valdmanis and Alistair Lyon)

Trending On Reuters

World Wrap

Thousands of Russians, many carrying red carnations, queued on Tuesday to pay their respects to Boris Nemtsov, the Kremlin critic whose murder last week showed the hazards of speaking out against Russian President Vladimir Putin. Full Article | Related Story